1. Field of the Invention
The present invention relates generally to battery compartment enclosures for electronic devices and the like. The present invention relates more specifically to a battery compartment modification to permit the use of an alternative type of battery in the compartment. Even more specifically the present invention relates to a retrofit, removable, adaptor assembly that extends and modifies the battery compartment of a night vision goggles device, and permits the continued use of the original battery compartment cap assembly.
2. Background of the Invention
Battery compartments for housing and connecting batteries used in powering various electronic devices such as night vision goggles, flash lights, camera light meters, etc., are well known in the art. Such battery compartment designs often include removable battery compartment caps which enable the battery or batteries contained within the compartment to be removed and replaced with new or recharged batteries.
One specific night vision device that incorporates a battery compartment that lends itself to modification to receive a preferred battery type is the AN/PVS-7B/7D night vision goggle manufactured by ITT Industries. Referring to FIG. 1A (prior art), there is shown a AN/PVS-7B/7D night vision goggle device 10 (illustrated in dotted outline form) which includes a horizontally oriented battery compartment 12, closed and covered by a removable (internally threaded) battery compartment cap 14. The battery compartment cap 14 is tethered to the night vision goggle device 10 by way of retainer strap 16. The battery compartment 12 is typically loaded with either lithium sulfur dioxide BA-5567/U batteries or two (2) AA batteries.
FIG. 1B shows in cross-section detail the typical configuration of battery compartment 12 enclosing a BA-5567/U battery 18 with battery compartment cap 14 secured in place. Electrical conductor 20 connects flat spring contact 22 (which contacts battery 18) with the electronics of the night vision goggle device 10. Tether 16 is attached to battery compartment cap 14 in such a manner as to permit easy rotation of the cap to thread onto the opening of battery compartment 12.
Efforts have been made in the past to improve the functionality of the battery compartment cap 14 but have generally not addressed modification of the battery compartment to accommodate alternate battery selections. U.S. Pat. No. 6,194,097 issued to Nelson et al. on Feb. 27, 2001 entitled Battery Compartment Cap Having an Improved Contact, assigned to ITT Manufacturing Enterprises, Inc. (the disclosure of which is incorporated herein by reference) describes an effort to improve the battery compartment cap for the night vision goggle device that is the subject of the present invention as well. Although the modification described improves the ability of the cap to maintain electrical contact with the batteries there is nothing disclosed that is directed to accommodating alternate battery choices for the device.
Although the battery compartment 12 (as shown in prior art FIGS. 1A and 1B) functions in a generally satisfactory manner, there exist certain disadvantages which reduce its utility. Battery selection is limited to two choices, either a single lithium sulfur dioxide BA-5567/U battery or two (2) AA batteries. The physical dimensions of the battery compartment were built around these two battery choices. An inability to procure either of these two battery choices, the BA-5567/U or the two AA batteries, could render the night vision goggle device inoperable or place it out of service.
Other problems with the existing design for the battery compartment and cap include concerns about misalignment of the electrical contacts when loading certain types of batteries and the excessive weight of certain types of batteries that the night vision goggle device is designed to be used with. A lithium battery, for example, will generally weigh less than the equivalent alkaline cell. The BA-5567/U batteries have a nominal weight of 16 g while the AA batteries have weights of 22 g-23 g each for a total battery weight of 44 g-46 g. The newer and now readily available CR123A battery, on the other hand, as an example of an alternate battery capable of providing the same voltage and a greater power output, has a nominal weight of 16 g-17 g.
Still another problem with the existing design concerns the expected capacity of the lithium sulfur dioxide BA-5567/U batteries or two (2) AA batteries. The BA-5567/U batteries have a nominal capacity of 0.86 AH while the AA batteries have capacities of 1.8 AH to 2.6 AH. By addressing the physical constraints of the original design, a different and more desirable battery, for example the CR123A, could be used. The CR123A has nominal 1.3 AH capacity which would extend use beyond the capacity of the BA-5567/U battery of the original design and yet would provide a much lighter weight battery at 16 g-17 g total than the AA batteries at 44 g-46 g total.
A further consideration in choosing a battery for the night vision device involves the frequent necessity of carrying spare batteries for the night vision device and the various other battery powered devices that may typically be carried. More of the various other battery powered devices (lights, electronic sights, etc.) are using the CR123A type batteries, making it desirable for the night vision device to likewise be capable of using such batteries. It would therefore be desirable if the user could either use such batteries directly within the night vision device or carry a lightweight adaptor that permitted such use. The result would be the need to carry spares of only a single type of battery rather than multiple sets of spares. As a further advantage to this approach, the user could transfer batteries from one device to another if spares were not available and the ongoing use of a particular device became urgent.
It is, therefore, a primary objective of the present invention to provide the ability to select a different battery combination to address the power output and weight issues and substantially overcome the disadvantages associated with the battery design selection and alignment of the prior art. The objective is to provide the ability to chose a more desirable “standard sized” battery for the AN/PVS-7B/7D night vision goggle system and at the same time, teach similar configurations for modifying and retrofitting other battery compartments for similar battery exchanges.
It is a further objective of the present invention to provide an apparatus for allowing the use of a more desirable battery, while at the same time not requiring permanent alteration of the base night vision goggle system. It would be worthwhile to have a modification structure that could be easily removed so as to allow the system to return to its previous use of battery choices.
It is a further objective that the above described modification structure would require a minimal number of components such that its use and/or its removal could be accomplished in the field without the need for tools to assemble or disassemble the night vision goggle system.
In particular, it is an object of the present invention to provide an adaptor assembly for the use of an alternate battery in the battery compartment of a night vision goggle system, that maintains the use of the existing battery compartment cap and cap tether. It is an object to permit placement of the adaptor assembly by opening the battery compartment (unscrewing the cap), removing the existing batteries from the night vision goggle system, replacing the existing batteries with the new battery/adaptor assembly, and then re-securing the threaded cap.
It is an object of the present invention to provide an adaptor assembly for allowing the use of an alternate battery in a night vision goggle system that is cost effective in providing a more efficient power source for the system without an excessive increase in the cost of the night vision goggle system itself.